Abstract Development and utilization of aged and genetically engineered mouse models are crucial to understanding the roles of specific genes in age-related hearing loss (ARHL). We will require strain-specific aged (senescent) mice that are not available commercially and are produced at the NIA-supported facility at the NIH, http://www.nia.nih.gov/research/dab/aged-rodent-colonies-handbook. All projects and Core C within the proposed PPG makes extensive use of these aged mice, and utilize a variety of genetic approaches to study the role of several genes in the inner ear and auditory neural pathways. Indeed, the proposed PPG will require the use of diseased models that result in hearing loss in the aging auditory system. The purpose of the mouse core is to provide services for the establishment of a strain-specific aged mouse colony and the generation and management of gene-targeted and transgenic mice. Founder mice will be identified, bred, and maintained in an animal facility at UNR. Additionally, several mouse lines will be bred and aged and supplied for experiments proposed in all three projects and Core C. The Core will also be responsible for maintaining and distributing mouse lines to each individual project. This will provide the most cost effective sharing and utilization of the mouse models. In addition, the Core will also cryopreserve critical lines in case of an inadvertent loss. Finally, the Core will be a resource for other laboratories interested in mouse models of ARHL.